WASHINGTON (AP) – A Delaware company that makes queso fresco and queso blanco was shut down by the Food and Drug Administration after an outbreak of listeria linked to the company's cheese killed one person and sickened seven others.

This is only the second time the FDA has used its authority to halt operations of a plant after gaining that authority in a 2011 food safety law. The agency said Tuesday that its inspectors found unsanitary conditions at Roos Foods in Kenton, Del., including a badly leaking roof, rusting and deteriorating machinery and food residues on equipment even after it had been cleaned.

The FDA said the agency took the action because food manufactured by the company could cause "serious adverse health consequences or death to humans." Listeria was found in some of Roos Foods' products and linked directly to the outbreak.

Roos can request a hearing on the decision, and the FDA can restart operations if the agency determines the health threat has been rectified. Calls to Roos Foods on Tuesday seeking comment were not returned.

The company has already recalled a large variety of its products, including many cheeses in its Amigo, Anita, Mexicana, and Santa Rosa de Lima brands.

Roos produces cheeses like queso blanco and queso fresco, which is commonly used in Hispanic foods, and all of those sickened were Hispanic. The products were distributed in Delaware, Maryland, New Jersey, New York, Virginia and the District of Columbia, though the death connected to the outbreak was in California. All of the other illnesses were in Maryland residents.

Three of those sickened were newborns; it is unclear if the death was one of the newborns.

Listeria is a foodborne illness that is especially dangerous to pregnant women, newborn babies and those with compromised immune systems. It rarely causes serious illness in healthy people and can be treated with antibiotics. Symptoms include fever, muscle aches, nausea and diarrhea.